The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
MPEG-4 emerged recently as an important development in the field of audio-visual coding aiming at establishing the first content-based audio-visual coding standard. This paper intends to analyse the current relation between MPEG-4 and very low bitrate video coding and corresponding applications, notably by considering the MPEG-4 objectives, functionalities and recent technical developments related...
In this paper we first describe the objectives of the Delft Mobile Multimedia Communications project. Next, the subject of lossy contour compression is considered in more detail as it is an essential component of most object or region-based compression techniques for low bit rate video coding. We propose an optimized B-splines approximation approach, which results in a 40 percent higher compression...
Visual text information is a descriptive part of many images that can be used to perform mobile visual search (MVS) with particularly small queries. In this paper, we propose a system that uses word patch descriptors for retrieving images containing visual text. A random sampling method is used to find duplicate word patches in the database and reduce the database size. The system achieves comparable...
Cloud computing is getting more popular in the field of computer science because of its reliability in storing and assessing data remotely. In the presence scenario it is very biter to have mobile devices as an interface between user and server, to access and store data for one's need. Mobile technology in cloud computing is helps users to operate on the data for any of the application for their organization...
This paper proposes the new coding rate control method in MPEG-2 video scalability. First of all, we investigate the efficiency of SNR scalability from the relations between hierarchical allocated bits and picture quality. Next, base on the the efficiency, we propose the new coding rate control method which has the dynamic controlling of bits allocation ratio. From the simulation experiments, we show...
The scope of the H.324 videophone standard includes mobile networks which can in bad radio conditions be susceptible to higher bit error rates than most fixed networks. Different parts of the H.263 video bit-stream have unequal importance in video signal reconstruction. For example, the contents of a video picture cannot be decoded unless a so-called picture header has been correctly received or successfully...
This paper presents some arguments in favour of further research in video compression because of scarce spectrum resources for mobile applications and the lack of powerful tools for scalable coding. Finally some ideas and results for metadata based compression, improved prediction and scalable schemes are presented.
Given the rise of ubiquitous computing and communication devices like biosensors, smart watch, and smartphones, real-time online systems can provide users with a wide range of supports including monitoring daily activities and retrieving of personal data. User activity pattern can give an abstraction and summarization about physical behavior for certain group of people. However, one of the biggest...
Mobile Augmented Reality (MAR) is an emerging field with a wide variety of applications involving the intricate challenges of computer vision. However, Mobile Augmented Reality for Inspection and Tele-Assistance (MARITA) is a relatively unknown entity which opens up new challenges in the field of wireless communications along with the existing computer vision hurdles. MARITA aims at providing augmented...
CISCO VNI predicted an average annual growth rate of 69.1% for mobile video traffic between 2013 and 2018 and accordingly much academic research related to video streaming has been initiated. In video streaming, Adaptive Bitrate (ABR) is a streaming technique in which a source video is stored on a server at variable encoding rates and each streaming user requests the most appropriate video encoding...
With the growing use of mobile technology to access health information, patients are being empowered in their healthcare choices. While specific mobile applications are becoming available for patients to manage their own care, most treatment processes support healthcare professionals and offer little support for patient centered care. In order to address this problem, federal regulations require providers...
Encoding multimedia streams of video calls is a very compute-intense task that significantly decreases battery lifetime of mobile phones. This paper introduces an approach to reduce power consumption of mobile phones by offloading video encoding efforts from mobile devices to external services. These services are hosted on servers co-located with cellular base stations. The paper describes how these...
Mobile psychological interventions are of growing interest, particularly for populations with little access to traditional mental health services. Optimum structural components of these interventions are unknown. In this study, twenty-one adolescents (age 13-17) with past two week depressive symptoms were recruited from the emergency department to participate in a semi-structured interview, to inform...
Conditional replenishment algorithm (CRA) was proposed to improve the quality of a hybrid 3DTV system with mixed resolution. Since CRA generates additional information which includes inter-view vectors, it is needed to efficiently encode the information. This paper proposes a method to apply differential pulse code modulation (DPCM) to the inter-view vectors so as to improve the coding efficiency...
In mobile multimedia services, preserving the battery life at the terminal is of utmost importance for user satisfaction, and suitable media processing at the device can be performed in order to reduce the brightness of the presented video, and to relent battery discharge. In this paper, we present a few experimental results assessing the impact, on the terminal power consumption, of a luminance preprocessing...
The popularity of cloud applications surged in the last years. Billions of mobile devices remain always connected. Location services, online games, social networking and navigation are a just few examples of "always on" cloud applications in which the same or partially overlapping content is delivered to multiple users. In this paper, we propose a technique, called NC-CELL, which uses network...
This paper presents a pilot study of testing a learning solution for smartphones, the Talking Tools (TT), under development. The study targets what, why, and when teacher students (N=11) use TT for microblogging about their work in a sloyd course. Their subjective reflections from a questionnaire using open-ended questions are used for validating earlier analysis of student blogs. Suggestions for...
For efficient multi-user distributed communications, near optimal beamforming techniques for multiple-input single-output interference channel with correlated block fading are proposed in this paper. Main idea is to find nearly optimal beamforming vectors a he present coding block based on optimal ones a the previous coding block. Under single-user decoding and Gaussian input constraint a each receiver,...
A mobile visual sensor network has a potential to create impacts in many applications in the society; however, it remains a challenge to keep the network lifetime as long as possible with limited onboard energy. Based on our previous work, mobility can be exploited to improve network lifetime significantly for data-intensive mobile sensor networks. In a visual sensor network, besides heavy data transmission,...
The performance of the mobile video broadcast is weakened when applying the traditional broadcast scheme which is forced to pick a single bit rate supported by the worst receiver. It leads to the drawback that receivers with better channels cannot obtain better video qualities. This paper proposed distributed Realcast, an analog video delivery scheme based on real value transmission, to provide differentiated...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.